YTM是怎么求出来的？

问题如下：

Consider a $100 par value bond, with an 8% coupon paid annually, maturing in 20 years. If the bond currently sells for $96.47, the yield to maturity is closest to:

选项：

A.

8.37%.

B.

8.29%.

C.

7.41%.

解释：

Correct Answer: A

A security with a present value of 96.47, 19 interest payments of 8, and a 20th payment of principal plus interest (108) has a yield to maturity of 8.37%.